Quinoidal Azaacenes: 99 % Diradical Character.

Sebastian N IntorpManuel HodeckerMatthias MüllerOlena TverskoyMarco RosenkranzEvgenia DmitrievaAlexey A PopovFrank RomingerJan FreudenbergAndreas Dreuw Uwe H F Bunz

Published in: Angewandte Chemie (International ed. in English) (2020)

Quinoidal azaacenes with almost pure diradical character (y=0.95 to y=0.99) were synthesized. All compounds exhibit paramagnetic behavior investigated by EPR and NMR spectroscopy, and SQUID measurements, revealing thermally populated triplet states with an extremely low-energy gap ΔEST' of 0.58 to 1.0 kcal mol-1 . The species are persistent in solution (half-life≈14-21 h) and in the solid state they are stable for weeks.

Keyphrases

solid state
atomic force microscopy
gestational age
energy transfer
mass spectrometry
quantum dots